Determine the composition of bile and gallstones from patients with carcinoma of the gallbladder. The study includes racial and ethnic groups, e.g. American Indians, who are known to have a high incidence of gallbladder cancer. Results indicate that Indians with gallbladder cancer have more glycolithicholic acid in bile than controls without cancer and that these patients do not completely sulfate the cholic acids. Reasons for incomplete sulfation are not presently known, but will be investigated. Non-sulfated cholic acids are toxic.